Field of the Invention
The present invention relates to peptides, proteins, nucleic acids and cells for use in immunotherapeutic methods. In particular, the present invention relates to the immunotherapy of cancer. The present invention furthermore relates to tumor-associated T-cell peptide epitopes, alone or in combination with other tumor-associated peptides that can for example serve as active pharmaceutical ingredients of vaccine compositions that stimulate anti-tumor immune responses, or to stimulate T cells ex vivo and transfer into patients. Peptides bound to molecules of the major histocompatibility complex (MHC), or peptides as such, can also be targets of antibodies, soluble T-cell receptors, and other binding molecules. In particular, the present invention relates to several novel peptide sequences and their variants derived from HLA class I and class II molecules of human tumor cells that can be used in vaccine compositions for eliciting anti-tumor immune responses or as targets for the development of pharmaceutically/immunologically active compounds and cells.
Description of Related Art
Hepatocellular carcinoma (HCC) is one of the most common tumors in the world and accounts for about 6% of all new cancer cases diagnosed worldwide. In 2012 about 782,000 new cases of HCC occurred in the world, making it the fifth most common cancer in men (554,000 cases) and the ninth in women (228,000 cases) (http://globocan.iarc.fr). HCC is the most common primary liver malignancy accounting for over 80% of all adult primary liver cancers.
The distribution of HCC varies geographically, and rates of incidence depend on gender. The age-standardized incidence rate (ASR) of HCC in men is highest in Eastern Asia (31.9) and South-Eastern Asia (22.2), intermediate in Southern Europe (9.5) and Northern America (9.3) and lowest in Northern Europe (4.6) and South-Central Asia (3.7). Incident rates of HCC in women are lower than male ASRs. The highest ASR in women occurs in Eastern Asia (10.2) and Western Africa (8.1), the lowest in Northern Europe (1.9) and Micronesia (1.6).
The overall prognosis for patients with HCC is poor. The 5-year relative survival rate (5Y-RSR) from HCC is about 15%, depending on the stage at the time of diagnosis. For localized HCC, where the cancer is still confined to the liver, the 5Y-RSR is about 28%. For regional and distant HCC, were the cancer has grown into nearby or distant organs, 5Y-RSRs are 7% and 2%, respectively.
The incidence of HCC is related to several risk factors, cirrhosis being the most important one. Cirrhosis often occurs alongside alcohol abuse or HBV or HCV infections, but can also be caused by metabolic diseases like type II diabetes. As a result, healthy liver tissue gets replaced by scar tissue, which increases the risk of cancer development.
Disease management depends on the tumor stage at the time of diagnosis and the overall condition of the liver. If possible, parts of the liver (partial hepatectomy) or the whole organ (liver resection) is removed by surgery. Especially patients with small or completely resectable tumors are qualified to receive a liver transplant.
If surgery is not a treatment option, different other therapies are available at hand. For tumor ablation, a probe is injected into the liver and the tumor is destroyed by radio or microwaves or cryotherapy. In embolization procedures, the blood supply of the tumor is blocked by mechanical or chemical means. High energy radio waves can be used to destroy the tumor in radiation therapy.
Chemotherapy against HCC includes combinations of doxorubicin, 5-fluorouracil and cisplatin for systemic therapy and doxorubicin, floxuridine and mitomycin C for hepatic artery infusions. However, most HCC show a high resistance to chemotherapeutics (Enguita-German and Fortes, 2014).
Therapeutic options in advanced non-resectable HCC are limited to Sorafenib, a multi-tyrosine kinase inhibitor (Chang et al., 2007; Wilhelm et al., 2004). Sorafenib is the only systemic drug confirmed to increase survival by about 3 months and currently represents the only experimental treatment option for such patients (Chapiro et al., 2014; Llovet et al., 2008).
Lately, a limited number of immunotherapy trials for HCC have been conducted. Cytokines have been used to activate subsets of immune cells and/or increase the tumor immunogenicity (Reinisch et al., 2002; Sangro et al., 2004). Other trials have focused on the infusion of Tumor-infiltrating lymphocytes or activated peripheral blood lymphocytes (Shi et al., 2004a; Takayama et al., 1991; Takayama et al., 2000).
So far, a small number of therapeutic vaccination trials have been executed. Butterfield et al. conducted two trials using peptides derived from alpha-fetoprotein (AFP) as a vaccine or DCs loaded with AFP peptides ex vivo (Butterfield et al., 2003; Butterfield et al., 2006). In two different studies, autologous dendritic cells (DCs) were pulsed ex vivo with autologous tumor lysate (Lee et al., 2005) or lysate of the hepatoblastoma cell line HepG2 (Palmer et al., 2009). So far, vaccination trials have only shown limited improvements in clinical outcomes.